Tracking bald eagle migrations for several years revealed that the birds begin to fly north in the summer and fly south again in the winter. While these migratory tendencies are associated with ...

Black-headed Grosbeaks (Pheucticus melanocephalus) have been observed to undergo prebasic molt during fall in the North American Monsoon region of the southwestern United States and northwestern ...

Arriving early in the breeding area is crucial for successful reproduction also in non-migratory birds. In birds, timing of arrival in a breeding area influences who ends up breeding and who does not.

Researchers found drier winters impact the likelihood of Kirtland’s warblers surviving migration and their ability to survive the breeding season. Credit: Nathan W. Cooper, Smithsonian’s National Zoo ...